Thing’s Opto switch and the Start button
It was back to the spurious Thing opto up switch problem again this weekend (where the Thing opto up switch turns off whenever the Left outlane switch is operated). Having tried to use a multimeter to measure the relevant switch matrix voltages to identify what was happening, I decided that because of the strobing nature of the signals, no sensible results could ever be achieved without the use of an oscilloscope – which is something I don’t have (although I did briefly have one, having succesfully won one on ebay. I had to send it back though, as it wasn’t working as advertised).
At the same time, however, the signal from the Thing opto up switch started to misbehave again, all by itself, showing intermittent shorts. Once again I took the plug off of the Thing opto baord and reseated all the wiring in the plug and reattached the plug to the opto board. Result – no more jittering. And no more “cross talk” between the Thing opto up switch and the Left outlane switch.
But then, the “cross talk” problem suddenly came back again.
Back to the drawing board for this problem. I need to discover whether the problem is with the CPU board or the opto board. Gut feel tells me the opto board at this stage (especially after my short-lived “success” having played with the plug…)
Also cleaned the Start button this weekend. The hardest part here was removing the switch/lamp assembly from the switch housing in order to completely remove the switch housing from the pinball body. The Extra Ball switch which I had bought has a push in and twist locking mechanism for the switch/lamp assembly, but this technique didn’t work at all on my Start button, however hard I tried. And I didn’t want to break the assembly. After much pulling, pushing and twisting, it turned out that the assembly was only push fitted into the housing. So a hard pull managed to free it from the switch housing, thereby enabling me to remove the whole switch, take it completely apart and clean it with soap and water. Reassembley was just as easy and now the switch feels like new!